U.S. patent application number 14/470579 was filed with the patent office on 2016-03-03 for systems and methods for sterilizing liquid media.
This patent application is currently assigned to ALGENOL BIOFUELS INC.. The applicant listed for this patent is Algenol Biofuels Inc.. Invention is credited to Alexander James Franke, Jesse Diego Phillips-Kress, Cyrus Nima Rashedi, Brendan Bodhi Scott, Jason Keith Ward.
Application Number | 20160060149 14/470579 |
Document ID | / |
Family ID | 55401700 |
Filed Date | 2016-03-03 |
United States Patent
Application |
20160060149 |
Kind Code |
A1 |
Scott; Brendan Bodhi ; et
al. |
March 3, 2016 |
Systems And Methods For Sterilizing Liquid Media
Abstract
Systems and methods for sterilizing liquid media such as saline
water using filtration and ozonation.
Inventors: |
Scott; Brendan Bodhi; (Fort
Myers, FL) ; Ward; Jason Keith; (Estero, FL) ;
Phillips-Kress; Jesse Diego; (Fort Myers, FL) ;
Rashedi; Cyrus Nima; (Estero, FL) ; Franke; Alexander
James; (Saint James City, FL) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Algenol Biofuels Inc. |
Fort Myers |
FL |
US |
|
|
Assignee: |
ALGENOL BIOFUELS INC.
Fort Myers
FL
|
Family ID: |
55401700 |
Appl. No.: |
14/470579 |
Filed: |
August 27, 2014 |
Current U.S.
Class: |
210/620 ;
210/137; 210/192; 210/739 |
Current CPC
Class: |
C02F 2201/784 20130101;
C02F 2209/40 20130101; C02F 2303/04 20130101; C02F 9/00 20130101;
C02F 3/322 20130101; C02F 1/444 20130101; C02F 1/78 20130101 |
International
Class: |
C02F 1/78 20060101
C02F001/78; C02F 3/02 20060101 C02F003/02 |
Claims
1. A system for sterilizing a liquid medium, the system comprising:
(a) at least one first filter capable of filtering the liquid
medium; (b) at least one ozone generator capable of adding ozone to
the liquid medium; and (c) connections providing fluid
communication between the at least one first filter and the at
least one ozone generator, wherein the at least one ozone generator
is downstream from the at least one first filter.
2. The system of claim 1, further comprising: (a) at least one
second filter capable of filtering the liquid medium; (b) at least
one flow control device; (c) at least one receptacle; and (d)
connections providing fluid communication among the at least one
first filter, the at least one second filter, the at least one
ozone generator, the at least one flow control device and the at
least one receptacle, wherein the at least one second filter is
downstream from the at least one first filter, the at least one
ozone generator is downstream from the at least one second filter,
the at least one flow control device is downstream from the at
least one ozone generator and the at least one receptacle is
downstream from the at least one flow control device.
3. The system of claim 2 wherein the at least one receptacle is a
photobioreactor.
4. The system of claim 2 wherein the liquid medium is saline
water.
5. The system of claim 2 wherein the at least one first filter is a
microfilter and the at least one second filter is an
ultrafilter.
6. The system of claim 5, further comprising: (a) at least one
Venturi injector configured to inject ozone from the at least one
ozone generator into the liquid medium; and (b) connections
providing fluid communication among the at least one first filter,
the at least one second filter, the at least one ozone generator,
the at least one flow control device, the at least one receptacle
and the at least one Venturi injector, wherein the at least one
Venturi injector is downstream from the at least one second
filter.
7. The system of claim 6, further comprising: (a) at least one tank
capable of receiving liquid medium from at least one of the at
least one first filter, the at least one second filter and the at
least one flow control device; and (b) connections providing fluid
communication among the at least one first filter, the at least one
second filter, the at least one ozone generator, the at least one
flow control device, the at least one receptacle, the at least one
Venturi injector and the at least one tank.
8. The system of claim 7 wherein the at least one tank receives
liquid medium from the at least one flow control device, further
comprising: (a) at least one ozone destruct device capable of
receiving gas from the at least one tank; and (b) connections
providing fluid communication among the at least one first filter,
the at least one second filter, the at least one ozone generator,
the at least one flow control device, the at least one receptacle,
the at least one Venturi injector, the at least one tank and the at
least one ozone destruct device.
9. The system of claim 8 further comprising at least one third
filter configured to filter gas received from the at least one
tank, wherein the at least one ozone destruct device is downstream
from the at least one third filter.
10. A system for sterilizing saline water, the system comprising:
(a) at least one receiving tank comprising an input for the saline
water and further comprising at least one output; (b) at least one
microfilter comprising an input for saline water received from the
at least one receiving tank and further comprising at least one
output; (c) at least one surge tank comprising an input for saline
water received from the at least one microfilter and further
comprising at least one output; (d) at least one ultrafilter
comprising an input for saline water received from the at least one
surge tank and further comprising at least one output; (e) at least
one supply tank comprising an input for saline water received from
the at least one ultrafilter and further comprising at least one
output; (f) at least one flow control device comprising an input
for saline water received from the at least one supply tank and
further comprising at least one output, wherein the at least one
output comprises at least one output of saline water to the at
least one supply tank and the at least one supply tank comprises an
input for saline water received from the at least one flow control
device; (g) at least one ozone generator capable of adding ozone to
the saline water between the at least one supply tank and the at
least one flow control device; (h) at least one Venturi injector
comprising an input for saline water received from the at least one
supply tank, an input for ozone received from the at least one
ozone generator, and at least one output for saline water to the at
least one flow control device; (i) at least one receptacle
comprising an input for saline water received from the at least one
flow control device, wherein the at least one flow control device
diverts saline water to the at least one receptacle and prevents
return of saline water from the at least one receptacle; and (j)
connections providing fluid communication among the at least one
receiving tank, the at least one microfilter, the at least one
surge tank, the at least one ultrafilter, the at least one supply
tank, the at least one flow control device, the at least one ozone
generator, the at least one Venturi injector and the at least one
receptacle.
11. A method for sterilizing a liquid medium, the method
comprising: (a) filtering the liquid medium using at least one
first filter; (b) filtering the liquid medium using at least one
second filter after filtering the liquid medium using the at least
one first filter; and (c) supplying at least a portion of the
liquid medium to at least one receptacle through at least one flow
control device after filtering the liquid medium using the at least
one second filter.
12. The method of claim 11, further comprising: (a) receiving the
liquid medium in at least one receiving tank before filtering the
liquid medium using the at least one first filter; (b) receiving
the liquid medium in at least one surge tank after filtering the
liquid medium using the at least one first filter and before
filtering the liquid medium using the at least one second filter;
(c) receiving the liquid medium in at least one supply tank after
filtering the liquid medium using the at least one second filter
and before supplying at least a portion of the liquid medium to the
at least one receptacle through the at least one flow control
device; and (d) receiving a remaining portion of the liquid medium
in at least one supply tank after supplying at least a portion of
the liquid medium to the at least one receptacle through the at
least one flow control device.
13. The method of claim 11 further comprising ozonating at least a
portion of the liquid medium using at least one ozone generator
after filtering the liquid medium using the at least one second
filter and before supplying at least a portion of the liquid medium
to the at least one receptacle through the at least one flow
control device.
14. The method of claim 13 further comprising ozonating the liquid
medium to a TRO concentration of at least about 5 milligrams per
liter, wherein the liquid medium is saline water, the at least one
first filter is a microfilter, the at least one second filter is an
ultrafilter and the at least one receptacle is a
photobioreactor.
15. The method of claim 14 further comprising testing for growth of
microorganisms in the liquid medium that has been filtered using
the at least one first filter, filtered using the at least one
second filter, and ozonated to a TRO concentration of at least
about 5 milligrams per liter, wherein no growth of microorganisms
occurs in the liquid medium after about 14 days.
16. The method of claim 13, further comprising: (a) receiving the
liquid medium in at least one receiving tank before filtering the
liquid medium using the at least one first filter; (b) receiving
the liquid medium in at least one surge tank after filtering the
liquid medium using the at least one first filter and before
filtering the liquid medium using the at least one second filter;
(c) receiving the liquid medium in at least one supply tank after
filtering the liquid medium using the at least one second filter
and before ozonating at least a portion of the liquid medium using
the at least one ozone generator; (d) receiving a remaining portion
of the liquid medium in at least one supply tank after supplying at
least a portion of the liquid medium to the at least one receptacle
through the at least one flow control device; and (e) destroying
ozone received from the at least one supply tank using at least one
ozone destruct device.
17. The method of claim 16 wherein the liquid medium is saline
water, the at least one first filter is a microfilter, the at least
one second filter is an ultrafilter and the at least one receptacle
is a photobioreactor.
18. The method of claim 17 further comprising ozonating the liquid
medium to a TRO concentration of at least about 5 milligrams per
liter.
19. The method of claim 17 further comprising ozonating the liquid
medium to a TRO concentration of at least about 10 milligrams per
liter.
20. The method of claim 19 further comprising testing for growth of
microorganisms in the liquid medium that has been filtered using
the at least one first filter, filtered using the at least one
second filter, and ozonated to a TRO concentration of at least
about 10 milligrams per liter, wherein no growth of microorganisms
occurs in the liquid medium after about 14 days.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM
LISTING COMPACT DISC APPENDIX
[0003] Not applicable.
BACKGROUND
[0004] Genetically enhanced microorganisms that make ethanol or
other biofuels through photosynthesis can be cultivated in
photobioreactors, in which cultures of the microorganisms are
provided with carbon dioxide and sunlight. Operation of a
photobioreactor entails inoculating the photobioreactor with
microorganisms in liquid media, such as saline water or fresh
water, to which nutrients and other growth agents are added.
[0005] Access to saline water typically is more prevalent and less
expensive than access to fresh water. To minimize cost, a supply of
saline water may be sourced, for example, from seawater or from
groundwater drawn from a saline aquifer.
[0006] Water drawn from uncontrolled sources such as seawater or
groundwater may contain microorganisms that are undesirable for
placement within a closed photobioreactor. Undesirable
microorganisms include fungi, bacteria, viruses, spore forms and
other microorganisms that, if added to a culture in a
photobioreactor, may outcompete the genetically enhanced
microorganisms in the culture and/or consume product made by the
genetically enhanced microorganisms.
[0007] Various approaches to treating water are the subject of, for
example, WO/2014/124357; U.S. Pat. App. Pub. No. 2010/0116647;
WO/2008/037324; U.S. Pat. App. Pub. No. 2004/0129645; U.S. Pat.
App. Pub. No. 2008/0035580; U.S. Pat. App. Pub. No. 2004/0061069;
U.S. Pat. App. Pub. No. 2007/0136834; U.S. Pat. App. Pub. No.
2012/0312757; U.S. Pat. App. Pub. No. 2004/0226893; U.S. Pat. App.
Pub. No. 2005/0155539; WO/2003/106350; U.S. Pat. App. Pub. No.
2011/0250604; U.S. Pat. No. 5,264,136; U.S. Pat. No. 5,888,428;
U.S. Pat. No. 7,052,601; U.S. Pat. No. 6,986,323; U.S. Pat. No.
5,250,177; U.S. Pat. No. 5,151,250; U.S. Pat. No. 3,459,528;
Perrins et al., "Ozonation of seawater from different locations:
formation and decay of total residual oxidant--implications for
ballast water treatment", Mar. Pollut. Bull. 2006 September;
52(9):1023-33; epub 2006 Mar. 15; Nielsen, "Control of Ballast
Water Organisms with a Seawater Electrochlorination and Filtration
System", a thesis submitted in partial fulfillment of the
requirements for the degree of Master of Science, University of
Washington 2006; Oemcke, "The treatment of ships' ballast water",
EcoPorts Monograph Series No. 18 (Ports Corporation of Queensland,
Brisbane), 1999, 102 pp.; Det Norske Veritas, "Technical Report,
Barber Ship Management, Ballast Water Treatment By
Ozonation--Corrosion", Report No. 2001-0522, Rev. No. 1, 2001; and
Sciortino et al., "Fishery Harbour Manual on the Prevention of
Pollution--Bay of Bengal Programme", BOBP/MAG/22, Madras, India
1999.
[0008] A need exists for a system and method of neutralizing and
removing microorganisms from water drawn from uncontrolled sources
to a degree that is satisfactory for use with cultures of
genetically enhanced microorganisms in closed photobioreactors.
Treating water for this purpose using on-demand production of
sterilizing agents, thereby avoiding on-site storage of potentially
toxic chemicals, is also advantageous.
SUMMARY
[0009] An object of the present invention is a system for
sterilizing a liquid medium such as saline water.
[0010] An aspect of this invention is directed to a system
comprising at least one first filter capable of filtering the
liquid medium; at least one ozone generator capable of adding ozone
to the liquid medium; and connections providing fluid communication
between the at least one first filter and the at least one ozone
generator, wherein the at least one ozone generator is downstream
from the at least one first filter.
[0011] An additional aspect of this invention is directed to a
system further comprising at least one second filter capable of
filtering the liquid medium; at least one flow control device; at
least one receptacle; and connections providing fluid communication
among the at least one first filter, the at least one second
filter, the at least one ozone generator, the at least one flow
control device and the at least one receptacle, wherein the at
least one second filter is downstream from the at least one first
filter, the at least one ozone generator is downstream from the at
least one second filter, the at least one flow control device is
downstream from the at least one ozone generator and the at least
one receptacle is downstream from the at least one flow control
device.
[0012] An additional aspect of this invention is directed to a
system wherein the at least one receptacle is a
photobioreactor.
[0013] An additional aspect of this invention is directed to a
system wherein the liquid medium is saline water.
[0014] An additional aspect of this invention is directed to a
system wherein the at least one first filter is a microfilter and
the at least one second filter is an ultrafilter.
[0015] An additional aspect of this invention is directed to a
system further comprising at least one Venturi injector configured
to inject ozone from the at least one ozone generator into the
liquid medium; and connections providing fluid communication among
the at least one first filter, the at least one second filter, the
at least one ozone generator, the at least one flow control device,
the at least one receptacle and the at least one Venturi injector,
wherein the at least one Venturi injector is downstream from the at
least one second filter.
[0016] An additional aspect of this invention is directed to a
system further comprising at least one tank capable of receiving
liquid medium from at least one of the at least one first filter,
the at least one second filter and the at least one flow control
device; and connections providing fluid communication among the at
least one first filter, the at least one second filter, the at
least one ozone generator, the at least one flow control device,
the at least one receptacle, the at least one Venturi injector and
the at least one tank.
[0017] An additional aspect of this invention is directed to a
system wherein the at least one tank receives liquid medium from
the at least one flow control device, further comprising at least
one ozone destruct device capable of receiving gas from the at
least one tank; and connections providing fluid communication among
the at least one first filter, the at least one second filter, the
at least one ozone generator, the at least one flow control device,
the at least one receptacle, the at least one Venturi injector, the
at least one tank and the at least one ozone destruct device.
[0018] An additional aspect of this invention is directed to a
system further comprising at least one third filter configured to
filter gas received from the at least one tank, wherein the at
least one ozone destruct device is downstream from the at least one
third filter.
[0019] An additional aspect of this invention is directed to a
system comprising at least one receiving tank comprising an input
for saline water and further comprising at least one output; at
least one microfilter comprising an input for saline water received
from the at least one receiving tank and further comprising at
least one output; at least one surge tank comprising an input for
saline water received from the at least one microfilter and further
comprising at least one output; at least one ultrafilter comprising
an input for saline water received from the at least one surge tank
and further comprising at least one output; at least one supply
tank comprising an input for saline water received from the at
least one ultrafilter and further comprising at least one output;
at least one flow control device comprising an input for saline
water received from the at least one supply tank and further
comprising at least one output, wherein the at least one output
comprises at least one output of saline water to the at least one
supply tank and the at least one supply tank comprises an input for
saline water received from the at least one flow control device; at
least one ozone generator capable of adding ozone to the saline
water between the at least one supply tank and the at least one
flow control device; at least one Venturi injector comprising an
input for saline water received from the at least one supply tank,
an input for ozone received from the at least one ozone generator,
and at least one output for saline water to the at least one flow
control device; at least one receptacle comprising an input for
saline water received from the at least one flow control device,
wherein the at least one flow control device diverts saline water
to the at least one receptacle and prevents return of saline water
from the at least one receptacle; and connections providing fluid
communication among the at least one receiving tank, the at least
one microfilter, the at least one surge tank, the at least one
ultrafilter, the at least one supply tank, the at least one flow
control device, the at least one ozone generator, the at least one
Venturi injector and the at least one receptacle.
[0020] Another object of the present invention is a method for
sterilizing a liquid medium such as saline water.
[0021] An additional aspect of this invention is directed to a
method comprising filtering the liquid medium using at least one
first filter; filtering the liquid medium using at least one second
filter after filtering the liquid medium using the at least one
first filter; and supplying at least a portion of the liquid medium
to at least one receptacle through at least one flow control device
after filtering the liquid medium using the at least one second
filter.
[0022] An additional aspect of this invention is directed to a
method further comprising receiving the liquid medium in at least
one receiving tank before filtering the liquid medium using the at
least one first filter; receiving the liquid medium in at least one
surge tank after filtering the liquid medium using the at least one
first filter and before filtering the liquid medium using the at
least one second filter; receiving the liquid medium in at least
one supply tank after filtering the liquid medium using the at
least one second filter and before supplying at least a portion of
the liquid medium to the at least one receptacle through the at
least one flow control device; and receiving a remaining portion of
the liquid medium in the at least one supply tank after supplying
at least a portion of the liquid medium to the at least one
receptacle through the at least one flow control device.
[0023] An additional aspect of this invention is directed to a
method further comprising ozonating at least a portion of the
liquid medium using at least one ozone generator after filtering
the liquid medium using the at least one second filter and before
supplying at least a portion of the liquid medium to the at least
one receptacle through the at least one flow control device.
[0024] An additional aspect of this invention is directed to a
method further comprising ozonating the liquid medium to a TRO
concentration of at least about 5 milligrams per liter, wherein the
liquid medium is saline water, the at least one first filter is a
microfilter, the at least one second filter is an ultrafilter and
the at least one receptacle is a photobioreactor.
[0025] An additional aspect of this invention is directed to a
method further comprising testing for growth of microorganisms in
the liquid medium that has been filtered using the at least one
first filter, filtered using the at least one second filter, and
ozonated to a TRO concentration of at least about 5 milligrams per
liter, wherein no growth of microorganisms occurs in the liquid
medium after about 14 days.
[0026] An additional aspect of this invention is directed to a
method further comprising receiving the liquid medium in at least
one receiving tank before filtering the liquid medium using the at
least one first filter; receiving the liquid medium in at least one
surge tank after filtering the liquid medium using the at least one
first filter and before filtering the liquid medium using the at
least one second filter; receiving the liquid medium in at least
one supply tank after filtering the liquid medium using the at
least one second filter and before ozonating at least a portion of
the liquid medium using the at least one ozone generator; receiving
a remaining portion of the liquid medium in the at least one supply
tank after supplying at least a portion of the liquid medium to the
at least one receptacle through the at least one flow control
device; and destroying ozone received from the at least one supply
tank using at least one ozone destruct device.
[0027] An additional aspect of this invention is directed to a
method wherein the liquid medium is saline water, the at least one
first filter is a microfilter, the at least one second filter is an
ultrafilter and the at least one receptacle is a
photobioreactor.
[0028] An additional aspect of this invention is directed to a
method further comprising ozonating the liquid medium to a TRO
concentration of at least about 5 milligrams per liter.
[0029] An additional aspect of this invention is directed to a
method further comprising ozonating the liquid medium to a TRO
concentration of at least about 10 milligrams per liter.
[0030] An additional aspect of this invention is directed to a
method further comprising testing for growth of microorganisms in
the liquid medium that has been filtered using the at least one
first filter, filtered using the at least one second filter, and
ozonated to a TRO concentration of at least about 10 milligrams per
liter, wherein no growth of microorganisms occurs in the liquid
medium after about 14 days.
[0031] The foregoing and other features and advantages of the
invention will become further apparent from the following detailed
description of the presently preferred embodiments, read in
conjunction with the accompanying drawings. The detailed
description and drawings are merely illustrative of the invention,
rather than limiting the scope of the invention being defined by
the appended claims and equivalents thereof.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0032] Embodiments of the invention will be described below with
reference to the following figures.
[0033] FIG. 1 shows a schematic or flowchart of a system or method
according to the present invention.
[0034] FIG. 2 shows a schematic or flowchart of a system or method
according to the present invention.
[0035] FIG. 3 shows a schematic or flowchart of a system or method
according to the present invention.
DETAILED DESCRIPTION
[0036] As used herein, the term "sterilize" or "sterilization"
means the elimination of substantially all microorganisms,
including transmissible agents (such as fungi, bacteria, viruses
and spore forms) contained in a liquid medium.
[0037] As used herein, the term "liquid medium" means liquid such
as saline water from seawater or groundwater, or fresh water.
[0038] As used herein, the term "growth medium" means liquid medium
that contains nutrients or other growth agents suitable for
supporting the growth of microorganisms.
[0039] As used herein, the term "saline water" means water that
contains dissolved salts at a concentration of from about 1,000 ppm
to about 35,000 ppm.
[0040] As used herein, the term "seawater" means saline water from
a sea or ocean.
[0041] As used herein, the term "groundwater" means water located
beneath the earth's surface in soil pore spaces and in the
fractures of rock formations, such as in an aquifer.
[0042] As used herein, the term "microfilter" means a filter
membrane with pore size of about 0.1 to about 10 microns, or
micrometers.
[0043] As used herein, the term "ultrafilter" means a filter
membrane with pore size of about 0.01 to about 0.1 microns, or
micrometers.
[0044] As used herein, the term "ozonation" means a treatment
method that destroys bacteria and other microorganisms in a liquid
medium through an infusion of ozone, which is a gas produced by
subjecting oxygen molecules to high electrical voltage. In saline
water, ozone oxidizes chloride, bromide and iodide. In seawater,
which contains approximately 67 milligrams per liter of bromide,
ozone oxidizes bromide into bromine, specifically hypobromous acid
and hypobromite ion.
[0045] As used herein, the term "flow control device" means a valve
or any other similar apparatus understood by one of ordinary skill
in the art to be suitable for controlling, for example, rate,
dispersion or distribution of flow of a liquid or fluid medium.
[0046] As used herein, the term "Venturi injector" means a
differential pressure injector, optionally with internal mixing
vanes.
[0047] As used herein, the term "fluid communication" means a
connection that permits the passage of liquids or gases.
[0048] As used herein, the term "photobioreactor" means a device or
system used to support a biologically active environment for the
cultivation of photosynthetic microorganisms.
[0049] As used herein, the term "total residual oxidant
concentration" or "TRO concentration" means the concentration of
oxidizing agents in a liquid medium.
[0050] As used herein, the term "oxidizing agent", "oxidant" or
"oxidizer" means the element or compound in an oxidation-reduction
(redox) reaction that accepts an electron from another species, and
is thereby reduced. In saline water, oxidizing agents may be, for
example, chlorine, bromine or iodine.
[0051] As used herein, the term "downstream" means of or pertaining
to the latter part of a system or process flow.
[0052] As used herein, the term "about" means approximately, in the
region of, roughly, or around. When the term "about" is used in
conjunction with a numerical value or range, it modifies that value
or range by extending the boundaries above and below the numerical
value(s) set forth. In general, the term "about" is used herein to
modify the numerical value(s) above and below the stated value(s)
within a confidence interval of 90% or 95%.
[0053] The present invention relates to systems and methods for
sterilizing liquid media such as saline water from seawater or
groundwater using filtration and ozonation. These and other aspects
of the present invention significantly benefit the operation of,
for example, photobioreactors used to cultivate genetically
enhanced microorganisms that make products such as ethanol or other
biofuels through photosynthesis. After being sterilized using
systems and methods of the present invention, a liquid medium is
free of microorganisms that may outcompete the genetically enhanced
microorganisms and/or consume product, and is suitable to be added
to a culture of genetically enhanced microorganisms contained in a
closed photobioreactor.
[0054] As shown in FIG. 1, a supply 1000 of a liquid medium such as
saline water from seawater or groundwater enters a system or method
of the present invention. The liquid medium successively flows
downstream into a receiving tank 1010, through a first filter 1020,
into a surge tank 1030, through a second filter 1040 and into a
supply tank 1050.
[0055] In some embodiments, the first filter 1020 or second filter
1040 is a microfilter. In some embodiments, the first filter 1020
or second filter 1040 is an ultrafilter.
[0056] In some embodiments, the liquid medium flows downstream from
the supply tank 1050 through a flow control device 1060. In some
embodiments, all or a portion of the liquid medium is in fluid
communication with an ozone generator 1070 downstream from the
supply tank 1050 and upstream from the flow control device 1060. In
some embodiments, ozone generated by the ozone generator 1070 is
added through a Venturi injector 1080 into a slipstream 1090 of
liquid medium that is drawn from a main flow 1100 of liquid medium
downstream from the supply tank 1050 and upstream from the flow
control device 1060.
[0057] In some embodiments, all or a portion of liquid medium
flowing through the flow control device 1060 may be supplied
downstream to a receptacle 1110 such as a photobioreactor or a
storage tank, with any remaining portion of liquid medium
recirculated to the supply tank 1050. In some embodiments, the
liquid medium flows through the flow control device 1060 and then
to the supply tank 1050, with no diversion of liquid medium to
receptacles 1110.
[0058] In some embodiments, the flow control device 1060
incorporates a one-way valve or other suitable apparatus that is
capable of dispersing liquid medium to both the supply tank 1050
and the receptacle 1110, while preventing reverse flow of liquid
medium from the receptacle 1110.
[0059] In some embodiments, a system or method of the present
invention incorporates a vent 1120 that allows gas to enter or
leave. In some embodiments, the vent 1120 is in fluid communication
with the supply tank 1050 and enables gas to enter or leave the
supply tank 1050 in response to decreases or increases in the
volume of liquid medium in the supply tank 1050, in order to
maintain pressure within a safe operating range and prevent over
pressurization of the supply tank 1050 when filling or collapse of
the supply tank 1050 when emptying. In some embodiments, the vent
1120 incorporates microfilters or ultrafilters, through which gas
entering or leaving the supply tank 1050 flows. In some
embodiments, gas that leaves the supply tank 1050 through the vent
1120 flows to an ozone destruct device 1130, which destroys ozone
before the gas is released to the atmosphere.
[0060] Without wishing to be bound by theory, a system or method of
the present invention sterilizes liquid media by removing
microorganisms and suspended particles using the first filter 1020
and second filter 1040, and killing microorganisms through
ozonation. Filtration reduces the load of microorganisms in the
liquid medium and thereby reduces the degree of ozonation needed to
kill microorganisms in the liquid medium. Filtration also reduces
total organic carbon present in the liquid medium, thereby reducing
the amount of ozone that is diverted to oxidizing carbon instead of
killing microorganisms. Ultrafiltration removes spore-forming
organisms that have high kill thresholds with ozonation. Ozonation
remediates microorganisms downstream from filtration and reduces
the load of microorganisms in the liquid medium by increasing TRO
concentration in the liquid medium.
[0061] Ozonation can be used in a system or method of the present
invention to increase the TRO concentration in filtered liquid
medium above a preselected minimum value that sterilizes the liquid
medium. In some embodiments, the liquid medium is ozonated to a TRO
concentration of about 10 milligrams chlorine per liter before the
liquid medium is supplied to a receptacle such as a
photobioreactor. In some embodiments, the liquid medium is ozonated
to a TRO concentration of about 5 milligrams chlorine per liter
before the liquid medium is supplied to a receptacle such as a
photobioreactor. One of ordinary skill in the art will understand
that units of milligrams chlorine per liter may be converted to
units of milligrams bromine per liter, for example, according to
the ratio of the atomic masses or molar masses of the elements.
[0062] The supply tank 1050, ozone generator 1070 and flow control
device 1060 of a system of the present invention comprise a flow
loop. Liquid medium that has been filtered and ozonated can be
recirculated in the flow loop continually and withdrawn from the
flow loop when supply to a photobioreactor or other receptacle 1110
is needed. The ozone generator 1070 can be selectively operated in
a system or method of the present invention to achieve and maintain
TRO concentration in the liquid medium in the flow loop at or above
a preselected minimum value, and thereby maintain sterility of the
liquid medium in the flow loop. Recirculation in the flow loop of
liquid medium that has been filtered and ozonated may also help to
maintain sterility of the fluid connections.
[0063] In some embodiments, liquid medium in the supply tank 1050
is recirculated to improve mixing of the liquid medium and
facilitate even distribution of oxidants in the liquid medium.
[0064] The receiving tank 1010, surge tank 1030 and supply tank
1050 provide a system or method of the present invention with
capability to store large volumes of sterilized liquid medium and
meet high surge demand when supplying the sterilized liquid medium
to multiple receptacles 1110.
[0065] In some embodiments, storage and surge capacity are not
required to supply sterilized liquid medium to receptacles 1110.
FIG. 2 shows a system or method of the present invention in which
liquid medium flows to a receptacle 1110, such as a
photobioreactor, via a first filter 1020, a second filter 1040, an
ozone generator 1070 and a flow control device 1060, with no tanks
connected among the components of the system or method. In an
embodiment as shown in FIG. 2, liquid medium is filtered and
ozonated by the system or method of the present invention only when
required for imminent or immediate use in the receptacle 1110. In
an embodiment as shown in FIG. 3, a system or method of the present
invention omits ozonation of the liquid medium by an ozone
generator 1070, and the liquid medium is filtered and then supplied
to a receptacle 1070.
Example 1
[0066] A system and method of the present invention comprise an
arrangement of components and method flow as indicated in FIG.
1.
[0067] The liquid medium to be sterilized is groundwater drawn from
a saline aquifer. The groundwater has substantially the same
salinity of 35 grams per liter and bromide concentration of 67
milligrams per liter as found in seawater.
[0068] The saline groundwater is pumped into a receiving tank. An
example of a suitable, commercially-available receiving tank is a
1500 gallon high-density polyethylene water storage tank from
Protectoplas Co.
[0069] The saline groundwater is then pumped downstream from the
receiving tank through a microfiltration unit, and then into a
surge tank. An example of commercially available filters used in a
suitable microfiltration unit are a 20 micron cartridge filter
(part number P-20-A-30-P) and a 5 micron cartridge filter (part
number P-5-A-30-P) from Rosedale Products, Inc. configured in
series, with the 20 micron cartridge filter upstream of the 5
micron cartridge filter. An example of a suitable,
commercially-available surge tank is a 1500 gallon high-density
polyethylene water storage tank from Protectoplas Co.
[0070] The saline groundwater is then pumped downstream from the
surge tank through an ultrafiltration unit, and then into as many
as eight supply tanks. An example of a suitable,
commercially-available ultrafiltration unit is a spiral membrane
ultrafiltration system with osmonics membranes (part number
817T-HZ20) from GE Osmonics, Inc. An example of a suitable,
commercially-available supply tank is a 2500 gallon high-density
polyethylene water tank with custom welded flange-style inlets and
outlets and gasketed manhole cover from Protectoplas Co.
[0071] The saline groundwater is then pumped downstream from the
supply tanks to a flow control device. The flow control device is
capable of distributing the saline groundwater downstream to one or
more receptacles on-demand. The receptacles may be, for example,
photobioreactors in which the saline groundwater may be used in
culturing microorganisms. The flow control device is also capable
of recycling all or any unused portion of the saline groundwater to
the supply tanks. An example of a suitable, commercially-available
flow control device is a 2 inch schedule 80 PVC ball valve (part
number TB1200STE) from Hayward Industries, Inc.
[0072] Downstream from the supply tanks and upstream from the flow
control device, a slipstream of saline groundwater is drawn from
the main liquid flow and passes through a Venturi injector, before
rejoining the main liquid flow. An ozone generator is in fluid
communication with the Venturi injector and is configured to add
ozone to the saline groundwater through the Venturi injector
on-demand. An example of a suitable, commercially-available Venturi
injector is part number 1584A-PVDF from Mazzei Injector Company,
LLC. An example of a suitable, commercially-available ozone
generator is a Waterzone ozone injection system (part number
WS-300) from Ozone Solutions, Inc.
[0073] A vent connected to each supply tank maintains safe
operating pressure in the supply tank by allowing ambient air to
enter when the supply tank is being drained or be expelled when the
supply tank is being filled. The vent incorporates a filter, and is
connected in fluid communication to an ozone destruct unit that
removes ozone before the air from the supply tank is vented to the
atmosphere. An example of a suitable, commercially-available filter
for use with the supply tank vent is part number LI3GUATCTC-E from
Zenpure Corp. An example of a suitable, commercially-available
ozone destruct unit is an ozone destruct (part number ODS-10H) from
Ozone Solutions, Inc.
[0074] TRO concentration can be measured in saline groundwater
drawn from a sample port anywhere in the flow loop between the
supply tank and the flow control device. In the present system, the
sample port is located between the ozone generator and the flow
control device. An example of a suitable, commercially-available
instrument for measuring TRO concentration is a single analyte
photometer (part number I-2019) from CHEMetrics, Inc.
[0075] Examples of suitable, commercially-available pumps used to
move the saline groundwater through the system are part number
SP15V-T-M215 from Finish Thompson Inc. or any pump with
specifications sufficient to circulate water through a specified
loop with the pump head constructed of oxidant-resistant materials
such as polyvinylidene fluoride or polytetrafluoroethylene.
[0076] Examples of suitable, commercially-available piping used to
connect the components of the system are constructed of
high-density polyethylene, polyvinylidene fluoride,
polytetrafluoroethylene or similar materials.
[0077] In operation of the exemplary system, saline groundwater is
added from the saline aquifer on-demand and at a typical flowrate
of 50 gallons per minute. The slipstream of saline groundwater that
is diverted from the main liquid flow downstream from the supply
tanks and upstream from the flow control device may constitute some
portion or all of the main liquid flow, depending on the total
volume of liquid to be supplied to receptacles. The ozone generator
may be used to inject ozone-containing gas at a concentration of 7%
and flowrate of 25 liters per minute into the slipstream of saline
groundwater. Under these operating conditions, and when the flow
loop between the supply tanks and the flow control device is
closed, a TRO concentration of about 10 milligrams chlorine per
liter in about 10,000 gallons of saline groundwater can be achieved
after about three to about four hours of ozonation. Thereafter, the
filtered, ozonated saline groundwater in the closed flow loop may
be ozonated for about one hour per day under the same operating
conditions in order to maintain the TRO concentration of about 10
milligrams chlorine per liter of saline groundwater.
Example 2
[0078] The system and method disclosed in Example 1 provide saline
water that is sterile. To confirm sterility, the saline water is
tested in growth medium for growth of microorganisms. After 14
days, no growth of microorganisms is seen in the mixture in the
container.
[0079] A suitable method for testing for growth of microorganisms
is to sample 4 liters of saline groundwater with high TRO
concentration from the flow loop between the supply tanks and the
flow control device into a pre-sterilized container such as a glass
bottle. After TRO concentration in the saline groundwater sample
decays to about 0 milligrams per milliliter, which will typically
occur in about 2 to 5 days, 500 milliliters of growth medium is
added to the container.
[0080] An example of a suitable, commercially-available growth
medium is CC broth. CC broth is prepared by adding 1 gram each of
peptone, yeast extract, glucose, sucrose and casein acid
hydrolysate to 500 milliliters of filtered saltwater, followed by
autoclaving the solution at sterilization settings of 121 degrees
Celsius for 30 minutes and then allowing the broth to cool to room
temperature. Once the solution has reached room temperature, 20
milliliters of sterile 50.times.BG11+ sodium thiosulfate anhydrous
stock is aseptically added inside a UV-sterilized laminar flow hood
with thorough mixing.
[0081] Separately, 50.times.BG11+Sodium Thiosulfate Anhydrous Stock
is prepared by combining 125 milliliters NaNO.sub.3 (600 g/L), 10
milliliters K.sub.2HPO.sub.4 (265 g/L), 1 milliliter Na.sub.2 EDTA
2H.sub.2O (50 g/L) and 50 milliliters TM stock (1000.times.) in a 1
liter bottle, then adding 814 milliliters of reverse osmosis water
and 4.78 grams of sodium thiosulfate anhydrous, and mixing until
dissolved using a stir bar. The mixture is then sterile-filtered by
vacuum filtration through a 0.22 micron bottle-top filter and
stored at 4 degrees Celsius.
[0082] Additionally, the productivity of microorganisms cultured in
saline groundwater that is treated using the system and method
disclosed in Example 1 is substantially the same as the
productivity of microorganisms cultured in saline groundwater that
is sterilized in an autoclave. This result further confirms the
efficacy of the system and method disclosed in Example 1 in
sterilizing the saline groundwater.
[0083] One of ordinary skill in the art will appreciate that a
system or method of the present invention can incorporate any
commercially available filters, ozone generators, tanks, pumps,
flow meters and other components that provide substantially similar
sterilization performance.
[0084] Although the present disclosure has been described in
considerable detail with reference to certain embodiments thereof,
other embodiments are possible. Therefore, the spirit and scope of
the appended claims should not be limited to the description of the
embodiments contained herein, and all changes that come within the
meaning and range of equivalents are intended to be embraced
therein.
* * * * *